Auto gearbox fault?

[bronty]

I have a Z3 2.8 1997 automatic
When I drive it from cold it drives great good gear change and smooth.
When I stop the car and switch off the engine then restart it drives off but on th 3rd gear change it jumps (feels like under the seat) then I get the engine management light on.It dose not go into limp mode just jump on high end gear change it feels like it jumps into gear.
If I switch the car let it go cold it runs fine again.
I have been told it could be a switch on the gearbox but unfortunately these switches are now obsolete
I am waiting for an adapter for obd so I am not sure what the fault code is.
I will take the car to a garage but not sure on a local garage that would be good with an old car.
Has any one had a similar problem?

 

[Stevo7682]

First thing to do is get the codes read as warning lights coming on there will be a code stored that will hopefully steer you in the right direction.

Stephen.

 

[bronty]

A quick update
I took the car to a automatic transmission specialist and he hooked is diagnostic to the car at a charge of £75
He did not look to assure and suggested a software update at £350 then if that fialed to change the Mechtronic unit
So before spending I bought the creator C310+ and an adaptor
It gave me two faults
08 air mass flow señor on the engine
99 CAN DME load signal
I have ordered a new mass flow señor and will see if that clears both faults
When I cleared the faults the car drives great again no jumping into gear

 

[t-tony]

Yeah, some specialist then eh?

Tony.

 

[Duncodin]

Yeah, some specialist then eh?

Tony.

Not much skill out there nowadays. They just don't teach it. They just plug it in and swap stuff out till the fault goes away.

 

[bronty]

I lost confidence when he had to borrow my adaptor to plug his OBD in

 

[bear2020]

I had an issue with my 3.0 but it was changing down. From 3rd to 2nd and then 2nd to 1st. It felt like someone stomping on the brakes. I renewed the auto fluid, changed the filter, changed diff fluid. Still did it. I then added some Dr Tranny Fluid https://www.britpart.com/all-parts/da6809 and instantly made a difference. Its not gone totally but probably because I knew it was there but to anyone else they do not know. Might be worth a try as I thought it was sensors and all sorts and at £15 thought it was worth a go

 

[bronty]

The New MAF arrived today I fitted it very simple 10 min job and it worked
No engine management light No gear jumping and drives smooth
Just need the sun to come out now

 

[colb]

So now you know not to take it to that garage ever again. Code reader and this Forum are your best friends going forward.

 

[bronty]

It is not the first time I have fallen foul of the garages
I had the dreaded critical gear box failure on a Range Rover after nearly 4k spent at experts. it turned out to be a Hydraulic torque limiter on the haldex pump found a bloke on the internet who fixed it for £180.